Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

<image>

In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Random;
import java.util.StringTokenizer;


public class Solution {
	
	
	boolean chk(int arr[][] ,  int n ,int m){
		
		int sum = 0;
		for(int i=0;i<n;i++){
			for(int j=0;j<m;j++){
				if(arr[i][j]!=0)
					return false;
			}
		}
		
	
			return true;
	
	}
		
	void solve() throws IOException{
	
			int n = in.nextInt();
			int m = in.nextInt();
			
			int arr[][] = new int[n][m];
			int temp[][] = new int[n][m];
			
			for(int i=0;i<n;i++){
				for(int j=0;j<m;j++){
					arr[i][j] = in.nextInt();
					temp[i][j] = arr[i][j];
				}
			}	
	
			int cnt1 = 0;
			StringBuilder st1 = new StringBuilder();
			
			for(int i=0;i<n;i++){
				int min = Integer.MAX_VALUE;
				 for(int j=0;j<m;j++){
					 min = Math.min(min,arr[i][j]);
				 }
				 if(min !=0){
					 cnt1+=min;
					 
					 for(int k=0;k<min;k++)
						 st1.append("row "+(i+1)+"\n");
					 for(int j=0;j<m;j++)
						 arr[i][j] -= min;
				 }
			}
			
			for(int i=0;i<m;i++){
			
					int min = Integer.MAX_VALUE;
					for(int j=0;j<n;j++){
						min = Math.min(min,arr[j][i]);
					}
					
					if(min !=0){
						cnt1+=min;
						for(int k=0;k<min;k++)
							st1.append("col "+(i+1)+"\n");
						
						for(int j=0;j<n;j++)
							arr[j][i]-=min;
					}
			}
			
		
			int cnt2 = 0;
			StringBuilder st2 = new StringBuilder();
			
			for(int i=0;i<m;i++){
				
				int min = Integer.MAX_VALUE;
				for(int j=0;j<n;j++){
					min = Math.min(min,temp[j][i]);
				}
				
				if(min !=0){
					cnt2+=min;
					for(int k=0;k<min;k++)
						st2.append("col "+(i+1)+"\n");
					
					for(int j=0;j<n;j++)
						temp[j][i] -=min;
						
					
					
				}
			}
			
			
			for(int i=0;i<n;i++){
				int min = Integer.MAX_VALUE;
				 for(int j=0;j<m;j++){
					 min = Math.min(min,temp[i][j]);
				 }
				 if(min !=0){
					 cnt2+=min;
					 for(int k=0;k<min;k++)
						 st2.append("row "+(i+1)+"\n");
					 for(int j=0;j<m;j++)
						 temp[i][j] -= min;
				 }
			}
			
			
			if(!chk(arr,n,m)&&(!chk(temp,n,m))){
				out.println("-1");
				return;
			}
			
			if(chk(arr,n,m)&&(!chk(temp,n,m))){
				out.println(cnt1);
				out.println(st1);
				return;
				
			}
			
			if(!chk(arr,n,m)&&(chk(temp,n,m))){
				out.println(cnt2);
				out.println(st2);
				return;
				
			}
			
			if(cnt1>=cnt2){
				out.println(cnt2);
				out.println(st2);
			}
			else{
				out.println(cnt1);
				out.println(st1);
			}
			
				
		
	} // solve
	
	long []suffle(long arr[] ,  int n){
		
		for(int i=0;i<n;i++){
			Random rad = new Random();
			int x = rad.nextInt(n);
			long temp = arr[x];
			arr[x] = arr[i];
			arr[i] = temp;	
		}
		
		return arr;
		
	}

	class FastScanner{
		BufferedReader br;
		StringTokenizer st;
	
		public FastScanner() {
			br = new BufferedReader(new InputStreamReader(System.in));
			st = new StringTokenizer("");
		}
		
		public int nextInt() throws IOException{
			 if(st.hasMoreTokens())
				return Integer.parseInt(st.nextToken());
			else{
				st = new StringTokenizer(br.readLine());
				return nextInt();
			}			
		}
		
		public long nextLong() throws IOException{
			 if(st.hasMoreTokens())
				return Long.parseLong(st.nextToken());
			else{
				st = new StringTokenizer(br.readLine());
				return nextLong();
			}			
		}
		
		public String readLine() throws IOException{
			return br.readLine();
		}
	}
	
	FastScanner in = new FastScanner();
	static PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out)); 
	
	
	public static void main(String args[])throws IOException{
		 new Solution().solve();
		 out.close();
	}
	
	
	

}